D =\(\left(-\dfrac{3}{5}x^3y^2z\right)^3=\left(-\dfrac{3}{5}\right)^3.\left(x^3\right)^3.\left(y^2\right)^3.z^3=-\dfrac{27}{125}x^9y^6z^3\)

đa thức D có bậc 9

hệ số : -27/125

Mark the letter A, B, C, or D on your answer sheet to indicate the word(s) CLOSEST in meaning to the underlined word(s) in each of the following questions.

It is such a prestigious university that only good students are entitled to a full scholarship each year.

A. have the right to refuse

B. are given the right to

C. are refused the right to 

D. have the obligation to

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions.

Let’s take actions to protect the environment, _____________ we?

A. needn’t

B. must

C. shall 

D. will

a) ta có \(\dfrac{x}{2}=\dfrac{y}{3}=\dfrac{z}{4}\Rightarrow\dfrac{2x}{4}=\dfrac{y}{3}=\dfrac{z}{4}\)

lại có: 2x+y-z=9

theo tính chất của dãy tỉ số bằng nhau ta có :

\(\dfrac{2x}{4}=\dfrac{y}{3}=\dfrac{z}{4}=\dfrac{2x+y-z}{4+3-4}=\dfrac{9}{3}=3\)

do đó :

x/2=3 => x=6

y/3=3 => y=9

z/4=3 => z=12

b) 2x=3y=5z

=> \(\dfrac{2x}{30}=\dfrac{3y}{30}=\dfrac{5z}{30}\Rightarrow\dfrac{x}{15}=\dfrac{y}{10}=\dfrac{z}{6}\Rightarrow\dfrac{x}{15}=\dfrac{2y}{20}=\dfrac{3z}{18}\)

lại có :x-2y+3z=65

theo tính chất của dãy tỉ số bằng nhau ta có:

\(\dfrac{x}{15}=\dfrac{2y}{20}=\dfrac{3z}{18}=\dfrac{x-2y+3z}{15-20+18}=\dfrac{65}{13}=5\)

Do đó :

x/15=5 => x=75

y/10=5 => y=50

z/6=5 => z=30

Mark the letter A, B, C, or D on your answer sheet to indicate the word(s) OPPOSITE in meaning to the underlined word(s) in each of the following questions.

It is relatively easy to identify the symptoms of the peculiar disease.

A. evidently

B. absolutely

C. comparatively

D. obviously